1. to add the 1st segment -B+C, obvious and enough to draw an arc cen­ter on -B with radius 1, which intersects at the point +C the ver­ti­cal to the half of A-B, as well as the arc from A radius phi at the point -D. 2. from -D clockwise to +E, and back to counterclockwise to -F, thanks to an arc from A, symmetrical to the previous on -B, radius = 1, in­ter­secting in -F the arc from -B with radius -BA. 3. from -F clock­wise to +G, then coun­ter­clock­wise to -H, 4. it's easy now, again to close a triangle (+G-H+I) and open another one (-H+I-J) 5. Need a fifth figure?